OBD-II code · Powertrain (generic)

P0777 Pressure Control Solenoid B Stuck On

Pressure control solenoid B does not release line pressure when commanded — output pressure remains at maximum, leading to harsh shifts and elevated stress on the clutch packs and seals.

Is it safe to drive with P0777?

Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.

Common causes

  • Most likelySolenoid stuck open by debris
  • PossibleContaminated ATF clogging the pressure control valve
  • Less likelyCarbon or debris buildup preventing free movement

Symptoms

  • Check engine or transmission warning light on
  • Harsh, delayed, or missing shifts
  • Possible limp mode (locked in one gear)
  • Slipping or shuddering during gear changes

Repair at a glance

Difficulty
Hard
DIY friendly
Best left to a mechanic
Typical labour
2–8 h
Emissions test
Usually unaffected
Parts involved
Pressure Control Solenoid B, Valve Body

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.